(a) Field of the Invention
The present invention relates to a signal detection system in a multiple input multiple output (MIMO) system and a method thereof. More specifically, the present invention relates to a signal detection technique in an MIMO system using a high level modulation technique.
(b) Description of the Related Art
Various studies of detection techniques for a multiple input multiple output (MIMO) system have been ongoing in a like manner of a multiple user detection technique of code division multiple access (CDMA). A linear detection technique, one of the detection techniques for the MIMO, is classified as a zero forcing method (ZF) using an inverse matrix of channels, and a minimum mean-squared estimate (MMSE) method considering noise amplification in the ZF method. While the linear detection technique is simple to be realized, the performance is quickly deteriorated compared to other detection techniques.
In an ordered successive interference cancellation (OSIC) method known as a vertical Bell Labs layered space time architecture (V-BLAST), the linear detection is repeatedly performed by detecting a proper quality data symbols, eliminating the effect caused by the previously detected symbols, and then detecting the data symbols. While the performance is expected to be improved in the OSIC method compared to conventional linear detection methods, its complexity may also be increased. In addition, a maximum likelihood (ML) method is for selecting a combination minimizing a cost function by calculating the cost function of all kinds of transmitted symbol candidates. However, in the ML method, complexity is increased according to the number of constellations varied by modulation methods and the number of antennas.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention, and therefore, unless explicitly described to the contrary, it should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known in this country to a person of ordinary skill in the art.